AUSTIN - Officials with the City of Austin filed a lawsuit in federal court Friday to challenge Senate Bill 4 (SB 4), the ban on so-called 'sanctuary cities'. The lawsuit alleges SB 4 violates of the U.S. Constitution.

"We want our day in court," Austin Mayor Steve Adler said minutes after the lawsuit was filed.

"For far too long, the legislature has been playing political football with the safety of our city," Adler added.

Austin's lawsuit is a motion to intervene, asking a judge to add the city to the lawsuit filed by the City of San Antonio and a handful of other organizations on Thursday. The Worker's Defense Project is one of the organizations listed in the lawsuit.

"Make no mistake about it, when Governor Abbott signed SB 4, he picked a fight with thousands of working families and immigrant families here in the State of Texas," said Jose Garza, Executive Director, of the Worker's Defense Project

Austin's lawsuit makes nine major claims in the lawsuit:

Texas has enacted a series of unconstitutional laws targeting Hispanic residents

After Gov. Abbott stated his intent to punish "sanctuary" jurisdictions, ICE conducted raids to retaliate against the polices of local elected officials

SB 4 increases immigration enforcement and threatens to penalize municipalities and policymakers who decline to follow the state's unconstitutional demands

The City of Austin is a "Welcoming City"; local officials have publicly expressed their support for immigrant communities and their opposition to SB 4

Gov. Abbott reiterated his intent to punish "sanctuary" cities and discourage immigration across the Texas border

Most immigrants who cross the Texas border are of Hispanic descent

Many residents and visitors are in Texas lawfully but cannot produce forms of identification required by SB 4

The lawsuit states the conclusion of these findings is SB 4 violates the Supremacy Clause of the constitution which states the US government has exclusive authority over immigration, not cities.

"Our police officers are not allowed to arrest someone for violating a civil offense," said Adler.

Being in the United States without proper documentation is a civil charge, not criminal. And Mayor Adler said he stands with police chiefs from across the state who say SB 4 threatens public safety by limiting the powers of a chief.

"He can say to the police officers, there's someone out there that, right now, who's dangerous. We think might be in the area, we want you to focus on that person and not do anything else other than to try and find this person. But under this law he wouldn't be able to do that," Adler said.

SB 4 requires all Texas law enforcement honor ICE detainers. The detainers are voluntary requests to hold someone who has been arrested in jail while their immigration status is investigated.

The bill also allows law enforcement to ask anyone who is detained, which includes being pulled over for a traffic violation, about their immigration status. Many fear this will lead to racial profiling.

Mayor Adler also expressed his concern about the impact SB 4 has on free speech.

"This law provides that an elected official, such as myself, could be removed from office for endorsing a policy that is contrary to Senate Bill 4. Lest there be any question, I am today endorsing a policy different than that set out in Senate Bill 4," said Adler.

Not only can an elected official be removed from office, but also face criminal charges.

The day after SB 4 was signed into law, Attorney General Ken Paxton sued the City of Austin, city leaders, Travis County leaders and MALDEF, asking a judge to declare the law constitutional. Adler, a former attorney, said that sets a troubling precedent.

"It alleges violations of a law that has not been violated because it's not effective," said Adler. "You just can't go about suing people for breaking the law because you think they're going to break a law."

"The state's action is premature and the state doesn't have standing to either questions, the constitutionality of its own law or to sue people for violating a law that's not in effect, " he added.

Austin City Council Member Greg Casar posted the city's legal filing Friday morning on Twitter.